The drive to cut Britain's carbon-dioxide emissions has been hit by companies' reluctance to obey new rules to reveal how much heat and light their buildings waste.

Nearly three-quarters of firms are flouting legislation requiring them to disclose energy performance details for the properties they sell or rent out, The Independent has learnt.

The refusal to comply with the law raises fresh doubts over this country's ability to meet a European Union target of reducing emissions by at least 20 per cent by 2020. Nearly one-fifth of UK emissions come from business and industry.

Thirteen months ago, the Government brought in legislation requiring "energy performance certificates" (EPCs) of commercial properties to be produced whenever a building is sold or leased out.

The documents, similar to those that householders have to supply when they sell their homes, assess a building's use of heat, light and water. They are regarded as an essential first step towards reducing buildings' emissions.

But a study by energy assessors Elmhurst Energy has concluded that only 28 per cent of commercial buildings marketed for sale or lease carry the legally required EPCs.

Grant Shapps, the shadow Housing Minister, said he was shocked by the low levels of compliance with the law. "If we're going to meet our legally binding climate-change targets, then we'll need to see urgent action," he said. "We know that meeting the challenge of climate change requires thousands of small steps to be taken. We will start by recognising the energy performance of all buildings, domestic or commercial."

EPCs are similar to the colour-coded labels provided with washing machines and refrigerators. They place properties into one of seven bands depending on their energy efficiency. But the requirement to produce them rests with companies putting the property on the market, rather than the agents handling the sale or rental of the building. Failure to comply with the law can carry a fine of £5,000.

Gavin Dunn, operations director of Elmhurst Energy, said the drive "is very much part of an attempt within the European Union and the UK to move towards decarbonising the economy.

"We need to reduce the energy consumption of every building, and the first step is to get the information about their efficiency."